Skip to Main Content
Book Chapter

Diagenesis, plagioclase dissolution and preservation of porosity in Eocene and Oligocene sandstones at the Greeley oil field, southern San Joaquin basin, California, USA

By
D. T. Nguyen
D. T. Nguyen
California State University, Bakersfield, Department of Geological Sciences, 9001 Stockdale Highway, Bakersfield, CA 93311, USA
Search for other works by this author on:
R. A. Horton, Jr
R. A. Horton, Jr
California State University, Bakersfield, Department of Geological Sciences, 9001 Stockdale Highway, Bakersfield, CA 93311, USA
Search for other works by this author on:
A. B. Kaess
A. B. Kaess
California State University, Bakersfield, Department of Geological Sciences, 9001 Stockdale Highway, Bakersfield, CA 93311, USA
Search for other works by this author on:
Published:
January 01, 2018

Abstract:

The Vedder (Oligocene) and Kreyenhagen (Eocene) sandstones at the Greeley oil field consist of arkosic to subarkosic arenites and wackes deposited in shallow marine environments. Burial depths of the Vedder sandstones exceed 3150 m and the reservoir temperature is 124°C. The Kreyenhagen sandstones are buried to greater than 3920 m and the reservoir temperature is estimated to be c. 135°C. These sandstones are currently at or very near their deepest burial depths.

The textural relationships of the diagenetic minerals suggest syndepositional formation of glauconite, phosphate and pyrite, followed by early precipitation of pore-lining clay coatings and carbonate cements along with framework-grain fracturing and possibly dissolution. With increasing burial, dissolution of the framework grains continued, accompanied by the albitization of feldspars, the formation of K-feldspar and quartz overgrowths, the precipitation of kaolinite and other clays and possibly the precipitation of late carbonate cements. Finally, hydrocarbon migration and the formation of pyrite occurred during late diagenesis.

Porosity preservation and reservoir quality are primarily the result of plagioclase dissolution occurring as the strata approached their current burial depths. Mass balance calculations indicate the significant export of aluminium out of the sands. Thus secondary porosity produced by plagioclase dissolution has replaced the primary porosity destroyed by compaction, and now accounts for the majority of the porosity in these rocks.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Reservoir Quality of Clastic and Carbonate Rocks: Analysis, Modelling and Prediction

P. J. Armitage
P. J. Armitage
BP Upstream Technology, UK
Search for other works by this author on:
A. R. Butcher
A. R. Butcher
Geological Survey of Finland, Finland
Search for other works by this author on:
J.M. Churchill
J.M. Churchill
Shell UK Ltd, UK
Search for other works by this author on:
A.E. Csoma
A.E. Csoma
MOL Group Exploration, Hungary
Search for other works by this author on:
C. Hollis
C. Hollis
University of Manchester, UK
Search for other works by this author on:
R. H. Lander
R. H. Lander
Geocosm, USA
Search for other works by this author on:
J. E. Omma
J. E. Omma
Rocktype, UK
Search for other works by this author on:
R. H. Worden
R. H. Worden
University of Liverpool, UK
Search for other works by this author on:
The Geological Society of London
Volume
435
ISBN electronic:
9781786202901
Publication date:
January 01, 2018

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal